1. Field of the Invention
The present invention relates to a method for determining a touch control position in a touch control input device into which control information is inputted by touching a control surface.
2. Description of the Related Art
Vehicles provided with a display unit fitted with a touch control function (hereinafter referred to as a touch tracer) have increased in numbers lately. Among display units fitted with a touch tracer, there is, for example, one which is provided with a display and a separate control pad for performing a touch control and which detects a touched position on the control pad, which position corresponds to a display screen on the display, by optical sensors.
Specifically, light emitting elements and light receiving elements are disposed so as to form a plurality of parallel optical axes, i.e., detecting lines, in the vertical direction and in the horizontal direction of the control pad. When an operator touches the surface of the control pad with a finger, the display unit judges a position of the center of mass of the finger on the control pad by beams, such as infrared rays which are emitted from the light emitting elements to the light receiving elements, being intercepted by the finger. The display unit outputs a coordinate position of the finger on the control pad on the basis of results of this judgment. The coordinate position of the finger is then, for example, transformed into a coordinate position on the display to be displayed thereon.
The display unit displays control items on the display when in displaying a control menu on the display; for example, three each in the vertical and horizontal directions. Thus, the operator can select a control item by controlling the touch tracer. The display unit is arranged so as to detect the touched position on the control pad of the touch tracer at this time and to select a control item on the display that corresponds to the touched position detected as described above.
In vehicles, a remote controller having the control pad is used in various modes; for example, fixed in a center console of the vehicle or held by hand. If the remote controller is fixed in the center console of the vehicle, the passenger traces or touch-controls the control pad of the touch tracer with a right or left thumb or by the forefinger. If the passenger holds the remote controller in a hand, the passenger generally traces or touch-controls the control pad with a finger of the other hand.
If the operator controls the touch tracer with the hand that is holding the remote controller, the operator mainly traces or touch-controls with the thumb.
However, when a position of the center of mass of a finger making a touch control is detected, the coordinate position detected may deviate from the intended position when the manner of holding the remote controller or the finger that is controlling the touch tracer is changed. In particular, a thumb performing touch control is inclined when the remote controller is held and controlled by one hand, so that a number of lines whose beams are intercepted by the thumb increases. Then, when the position of the center of mass of the thumb is judged from the lines whose beams are intercepted, a deviation arises between the intended position and the control position calculated from the position of the center of mass of the thumb.
To prevent erroneous operations and to allow control by blind touch when the touch tracer is used in a remote controller of a navigation system and the like, it is preferable to reduce area of the control pad, a tracing area, and to reduce coordinate resolution. However, when the resolution is reduced, the detected position of the center of mass of the finger may deviate largely from the intended position, depending on how touch control is performed.
Therefore, the burden on the operator in performing touch control becomes large, because the operator must perform control while being aware of deviation between an intended control position and a detected control position and must perform control while watching the display.
The present invention has been devised in view of the above-mentioned facts and provides a touch control position determining method which allows the touch control position to be determined precisely regardless of modes of control.
In a first aspect of the invention for achieving the above-mentioned object, there is provided a method for determining a touch control position on a control pad, including the steps of (a) detecting at least one of a plurality of horizontal position detecting lines, which are formed in parallel in a vertical direction of the control pad by beams irradiated in the vertical direction from light emitting sections to light receiving sections, and at least one of a plurality of vertical position detecting lines, which are formed in parallel in a horizontal direction of the control pad by beams irradiated in the horizontal direction from light emitting sections to light receiving sections; and (b) in a case in which interception of at least one of the plurality of horizontal position detecting lines or at least one of the plurality of vertical position detecting lines is detected in Step (a), determining a control position on the control pad on the basis of positions of at least one of the horizontal position detecting lines which is not intercepted and at least one of the vertical position detecting lines which is not intercepted.
According to the first aspect, the detecting lines are provided in the horizontal direction which is the direction of right and left from the point of view of the operator who makes a touch control on the control pad and in the vertical direction which is the direction of approaching/separating to/from the operator by the horizontal and vertical position detecting lines so that beams of the detecting lines are intercepted when the touch control is made. The touch control position on the control pad is judged from the position of the detecting lines whose beam is not intercepted.
The light beams are not intercepted at least in the detecting lines separated from the touch control position when the touch control is made on the control pad. Therefore, it becomes possible to determine the touch control position intended by the operator from the detecting lines whose beams are not intercepted.
A second aspect of the invention is the method of the first aspect of the invention, wherein, in a case in which the control pad is divided into three areas in the horizontal direction: the step (a) detects interception of at least one of horizontal position detection lines which are respectively formed in the vertical direction at both horizontal direction end portions of the control pad; and the step (b) determines control to be at one of said three areas, on the basis of a position of at least one of said horizontal position detection lines which is not intercepted.
According to the second aspect, the horizontal position detecting lines are provided so that the light beams are intercepted when the touch control is made at the both ends in the horizontal direction to judge one of the three areas where the touch control position is located from the horizontal position detecting lines.
It is then possible to determine that the area where the touch control is made is the center when the detecting lines at the both ends are not detected.
It is also possible to determine that the area where the touch control is made is the other end when either one end of the detecting lines at the both ends is not detected.
Thus, the vertical position detecting lines and horizontal position detecting lines allow the judgment to be made along the intention of the operator who makes the touch control by judging the touch control position from the position of the non-detected detecting lines whose beams are not intercepted. The touch control position may be judged more precisely regardless of the state of control as compared to the case of finding the position of the center of mass of the finger from the detecting lines whose beams are intercepted and of determining this center of mass position as the touch control position.
Further, it allows the touch control position to be determined with low resolution because it is not what determines the center position when the touch control is made and the detecting lines need not be provided at tight intervals. In addition to that, it allows a number of parts for forming the detecting lines to be reduced and power consumed to detect the touch control to be suppressed.
A third aspect of the invention is the second aspect of the invention, wherein, in a case in which all of the horizontal position detecting lines respectively formed at the both end portions are not intercepted,step(b) determines that the control position is a center area.
According to the third aspect, it is judged whether or not a touch control has been made by the horizontal position detecting lines and when it is judged that the touch control has been made, the touch control position in the vertical direction is determined by the vertical position detecting lines. At this time, the horizontal position detecting lines may be disposed at intervals which allow to detect the touch control.
It also allows the power consumption to be suppressed as compared to the case of detecting whether or not a touch control has been made by the vertical and horizontal position detecting lines.
According to a fourth aspect of the invention, the vertical position detecting lines are detected in order from the vertical position detecting line positioned at either one of the outermost ends to the other outermost end in detecting whether or not the vertical position detecting lines are intercepted.
The fourth aspect is the second aspect of the invention, wherein in a case in which, of the horizontal position detection lines respectively formed at the both end portions, only one horizontal position detection line at one end portion is not intercepted, step (b) determines that the control position is an area portion at another end portion.
An operator places the finger tip at intending position in making a touch control in general. Therefore, the finger tip comes to the side distant from the operator, not the side closer to the operator, among the vertical position detecting lines. Accordingly, the finger tip is positioned in the vicinity of the detecting line distant from the operator among the vertical position detecting lines whose beams are intercepted and it becomes possible to determine the position precisely by determining the touch control position from this vertical position detecting line.
In a fifth aspect, there is provided a control pad, including: a plurality of horizontal position detecting lines formed in parallel in a vertical direction of the control pad by beams irradiated in the vertical direction from light emitting sections to light receiving sections; a plurality of vertical position detecting lines formed in parallel in a horizontal direction of the control pad by beams irradiated in the horizontal direction from light emitting sections to light receiving sections; a detector for detecting interception of at least one of the plurality of horizontal position detecting lines and at least one of the plurality of vertical position detecting lines; and a judging device for determining a control position on the control pad on the basis of positions of at least one of the horizontal position detecting lines which are not intercepted and at least one of the vertical position detecting lines which are not intercepted.
It is noted that the control pad has the same effects with the touch control position determining method of the first through fourth aspects described above, so that the aspects thereof will be omitted here.